MULTIPLE NEUROMATA OF THE CENTRAL NERVOUS SYSTEM. 729 
scHowsky thus declares himself to be asupporter both of the outgrowth and intercellular 
bridge theories of development. 
Marinesco and MineEa (1906-1909) have looked for evidence of regeneration of 
central nerve fibres in cases of experimental section of the cord in dogs and in compres- 
sion of the cord in man. They believe that a certain amount of restoration may take 
place through the formation of new fibrils, but that this can rarely go on to functional 
restoration as the re-establishment of the inter-neuronal connections of the new fibres 
would be almost impossible. Both in experimental and pathological conditions fibres 
of new formation can pass into the cicatrix from both upper and lower ends. The new 
fibres are of fine calibre, show moniliform swellings, and end in cénes and massues. 
They are derived, as in peripheral nerves, from the dissociation of the preserved axis- 
cylinder with successive ramifications: collateral branches may also be given off and 
these divide and ramify. The vessels, especially at the periphery of the cord, are 
surrounded almost with a plexus of new fibres. 
Marinesco and Mrnea attribute an important role to the presence of the cellules 
apotrophiques which are found in the tissue between the interrupted fibres. These are 
fusiform cells which frequently form protoplasmic bands as in the peripheral nerves. 
They have chemiotactic and nutritive properties in relation to the new fibres which 
may be found even within the protoplasm of the cells. CasaL has stated that in 
hemisection of the cord in cats the new fibres atrophy in consequence of the absence of 
cells capable of secreting a chemiotactic substance. Manrinesco has also described the 
neurotisation of areas of cerebral softening, tubercular and syphilitic nodules, and 
gliomas by means of bundles of fine fibres which form a reticulum around the lattice 
and tumour cells or within the vessel sheath. Here again there can be no functional 
restoration, and there is no intimate relation between the new fibres and the actual 
elements of new formation to register a symbiosis. 
Miyake (1908), using Cajal’s silver methods, compares the changes of the axis- 
cylinder in pathological processes and in experimental sections of the cord. He found 
at the margin of cerebral tumours vacuolation and terminal varicose swellings of the 
-axis-cylinders. Such swellings often showed the dissociated fibrils ending in rings and 
buds. In a sarcoma of the dura, which had no association with the brain, similar 
appearances were found in the vessels. ‘To determine whether the above changes were 
degenerative or regenerative Miyake carried out a series of experimental sections of the 
cord in rabbits. In the necrosed zone and the zone of reaction the axis-cylinders showed 
terminal swellings and vacuolation, but adjoining the healthy zone there was a dis- 
sociation of the axis-cylinder into fibrils with terminal cones—probably regenerative. 
The author has come to the conclusion that only terminal buds and rings following a 
fine axis-cylinder can be looked upon as signs of regeneration, and that even these 
must be accepted with great caution as they were found in the dural sarcoma. 
Rossi (1909) found, in aseptic hemisection of the cord in young rabbits and dogs, 
that there was a very manifest production of new fibres which pass the zone of 
“TRANS. ROY. SOC. EDIN., VOL. XLVIII. PART III. (NO. 27). 105 
